New Jersey Attorney General Jeffrey Chiesa speaks at a news conference in Treton today after Gov. Chris Christie appointed him to the late Frank Lautenberg's U.S. Senate seat.
(Tony Kurdzuk/The Star-Ledger)

TRENTON — Gov. Chris Christie today named New Jersey attorney general Jeffrey Chiesa to fill the Senate seat left vacant by the death of U.S. Sen. Frank Lautenberg.

Chiesa said he won't seek election later this year.

Christie's announcement at a hastily arranged news conference ended days of intense speculation over whom the Republican governor would appoint to serve nearly five months before voters elect a replacement for the 89-year-old Lautenberg, who died Monday.

New Jersey voters haven't sent a Republican to the Senate in four decades.

Some Republicans have criticized the approach as a political move on Christie's part, aimed at keeping Newark Mayor Cory Booker — who has expressed interest in the Senate seat — off the November ballot. Booker could attract more Democrats to come out to vote and possibly erode Christie's margin of victory over his Democratic opponent, state Sen. Barbara Buono.

Chiesa grew up in in Bound Brook with two younger sisters. His father worked at a chemical plant and died when Chiesa was 8, leaving his mother — a public school teacher — to raise him and his two sisters. He graduated from Notre Dame in 1987, and returns every year to see a football game. He earned his law degree from the Catholic University of America in 1990 and a year later joined the Cranford law firm now known as Dughi & Hewit. It was there that he met Christie.

Chiesa followed Christie to the U.S. Attorney's Office in 2002. He became Christie's trusted eyes and ears, and led some of the office's most high-profile public corruption cases, like the one against former state Senate president John Lynch. He moved again in 2009 after Christie was elected governor, taking the reins of his transition team.

He told The Star-Ledger that year that he wanted to help Christie hit the ground running "because I'm personally and professionally so invested in seeing him succeed."

He was named Christie's chief counsel when the governor took office.

Their close relationship has spawned questions about how well Chiesa would be able to stand alone as attorney general.

When he appointed Chiesa attorney general, Christie said he was bringing a "no-nonsense" approach to law enforcement. Those who went toe to toe with Chiesa in the courtroom said he never had a political agenda.

After two years of dealing with some of the most controversial policy matters as chief counsel, Chiesa won fans in both parties.